Display woocommerc shop page Gallery item

<style>

flex-control-thumbs {
  width: 90%;
  position: absolute;
  bottom: 0px; 
  text-align: center;
  display:flex;
  flex-wrap:nowrap;
  
  border: 1px solid red;
  overflow-x:auto;
  padding-bottom:10px;
}

.flex-control-thumbs li {
  margin: 0 6px;
  display: inline-block;
  zoom: 1;
}


.flex-control-thumbs li,
.flex-control-thumbs li:first-child {
  width: 10%;
  vertical-align: top;
  margin: 5px 1% 0 0;
  min-width: 60px;
}

.flex-control-thumbs img {
  width: 100%;
  display: block;
  opacity: 0.8;
  cursor: pointer;
}

.flex-control-thumbs img:hover {
  opacity: 0.5;
}

.flex-control-thumbs .flex-active {
  opacity: 1;
  cursor: default;
}

.product_slider .flex-active-slide a:hover {
  cursor: -webkit-zoom-in;
  cursor: -moz-zoom-in;
}


ul.flex-direction-nav {
    position: absolute;
    top: 30%;
    z-index: 99999;
    width: 100%;
    left: 0;
    margin: 0;
    padding: 0px;
    list-style: none;}

li.flex-nav-prev {float: left;}
li.flex-nav-next {float: right;}
a.flex-next {visibility:hidden;}
a.flex-prev {visibility:hidden;}
a.flex-next::after {visibility:visible;content: '\f105';
    font-family: FontAwesome;margin-right: 10px;font-size: 70px;    }
a.flex-prev::before {
    visibility:visible;
    content: '\f104';
    font-family: FontAwesome;    margin-left: 10px;font-size: 70px;
</style>

add_action('woocommerce_shop_loop_item_title','wps_add_extra_product_thumbs', 15);
function wps_add_extra_product_thumbs() {

	if ( is_shop() ) {

		global $product;

		$attachment_ids = $product->get_gallery_attachment_ids();
		wp_enqueue_script('flexslider');
		echo '<div class="flexslider"><ul class="flex-control-nav flex-control-thumbs product-thumbs slides">';

		foreach( array_slice( $attachment_ids, 0,3 ) as $attachment_id ) {


		  	$thumbnail_url = wp_get_attachment_image_src( $attachment_id, 'thumbnail' )[0];

			echo '<li data-thumb="' . $thumbnail_url . '">';
		  	echo '<img  src="' . $thumbnail_url . '">';
		  	echo '</li>';


		}

		echo '</ul></div>';
	
	}

 }